Water-tight electrical connector



Oct. 11, 1966 A. KLINGER WATERTIGHT ELECTRICAL CONNECTOR 2 Sheets-Sheet l Filed Sept. 4. 1963 Q Q e nl @W 'I l |,H., l m //M C W 1 /nvenors FLfve Kng?! mwa 2 7am/ji 5 P Httovnes Oct. 11, 1966 A. KLINGER WATER-TIGHT ELECTRICAL CONNECTOR 2 sheets-sheet z Filed Sept. 4. 1965 lnvenior: HL-fve Kl'LnSeY z 18 mm2 fl 35 'o Httornetsxw United States Patent O 7 Claims. (Cl. 339-60) The present invention relates to a water-tight connector for high-power electric `cables which are mounted within drill tubing through which water is circulated.

Drilling machinery is generally provided with tubular piping adapted to extend into a bore hole. The drilling motor is often located at the lower end of the tubing so that electrical cables have to be provided for supplying electric power to the motor. These cables thus pass through the tubing which also serves as a conduit for water Iwhich is piped, under pressure, to the drill located at the bottom. The tubing conventionally is made up of sections of given lengths, which sections are then added to the top-most end of the tubing already in the bore hole. This, of course, also means that the individual cable sections have to be connected to each other by means of water-tight connectors. The connector fittings, such as the plug component and the socket component, are mounted Within the tubing, the arrangement being such that when the individual tube sections are then connected to each other by means of sleeves, the electrical connection is effected at the same time without it being necessary to provide any special means for accomplishing this.

Experience has shown that the individual tube sections are handled very roughly and are exposed to extreme wear. This, as well as the fact that the electrical connection must be reliably established upon coupling of the tube sections, has made it necessary to take special precautions to make sure that the connector components joining the electrical cables in the individual tube sections properly and firmly establish the electrical contact. In particular, the arrangement has to be such that the contact surfaces of the cooperating connector elements are in good surface-to-surface contact with each other,

and that foreign bodies, such as dirt, sand, and so on, which may seep into the tubing, will not adversely affect the quality of the electrical connection.

It has -been found exceedingly diicult to provide -drill tubing which meets the above criteria, and one area which has given particular troubles is the problem of introducing and sealing the cables water-tightly into the connector fittings.

Many attempts have been made to provide suitable Ways of accomplishing the above. One proposed solution involves vulcanizing a transition sleeve to the cable at the point at which it makes contact with the connector, the purpose of which sleeve is to produce a good seal. The high pressure prevailing Within the tubing, however, will inevitably work its way through the cable and sleeve and ultimately reach the conductive parts, so that the electrical connection made by the connector will be adversely affected.

It has also been proposed to fill the junction between the cable and the connector plug with plastic material which is injection-molded into place. This makes it necessary to provide suitable means for heating the plastic and for introducing it under pressure, which has been found to be a most impractical, expensive and complicated approach when it is borne in mind that the connection is to be made in the field.

According to yet another proposal, a conical sealing element is pressed, by means of a clamping cone, against Patented Oct. 11, 1966 ice the plug or socket casing and the cable so as to be in sealing relationship therewith, lwhereupon the cable fitting is cast with a sealing mass. that at very high water pressure, of the order of 500 atmospheres, even this arrangement does not afford a sufiiciently reliable seal.

Also known is a fitting, used in deep-bore drilling operations, in which the contact elements are embedded in an elastically yielding material, such as soft rubber, which itself is arranged within the metallic casing; this arrangement has been found to provide -a good -contact thanks to the resilient seating of the contact elements. But this arrangement, too, has been found to have a number of drawbacks which make it impractical, one of them being that the soft rubber will not make homogeneous contact with the other material of which the fitting is made, and another of them being that the vulcanization requires equipment that is not readily available and usable in field operation.

It is, therefore, an object of the .present invention to provide a water-tight connector for high-power electric cables, for use in drill tubing which also carries water under high pressure (200 or more atmospheres), which connector overcomes the above drawbacks, is readily mass-producible at low costs, does not require any special equipment for effecting the connection, and is able to provide an excellent electrical connection between the cables of the individual tube sections.

With the above object in view, the present invention resides mainly in a connector of the above type in which the connector parts, i.e., the plug and socket components, are iixedly clamped and mounted on the ends of the tubular sections by means of multiple-piece clamps, and wherein the cable is pressed into sealing engagement with the body of' the connector, preferably by means of a clamping and sealing cone and is cast with a sealing material interiorly of the casing of the component. According to the present invention, the sealing material for the casings mounted within the tubing comprises at least one epoxy resin and at least one polymer which can be worked under normal pressure, the Shore hardness of which material is different at different places, this difference 4being obtained lby varying the ratio of the constituents. The Shore hardness of the sealing material is approximately in the region where the cable leads in, and lis substantially less, namely, about 35 to 65, in the region where the elements that actually effect the electrical contact are located.

According Ito another feature of the present invention, the contact elements are constituted by sleeves which are axially slitted from both directions, the slots extending past the middle. The sleeves are also provided with inwardly extending flanges or collars so that a wide ringshaped recess is formed in the axial middle of the sleeve.

According to another feature of the present invention, the connector components are attached to the tubing within Which Ithey are located by means of clamps made of two complementary pieces which encompass the connector component to be mounted and which themselves are held together solely lby means of the bolts which mount the clamps in the tubing.

Additional objects 4and advantages of the present invention will become apparent upon consideration of the following description when taken in conjunction with the accompanying drawings in which:

FIGURE l is a longitudinal sectional view of the male component, or plug, of the connector according to the present invention.

FIGURE 2 is -a longitudinal view of the female component, or socket, of the connector according to the present invention.

`But experience has shown Y Y cable 9 is pre-tensioned by means of a clip 13.

FIGURE 3 is a side view, partly in section, of a sleeve incorporated in a connector according to the present invention.

FIGURE 4 shows the sleeve ofVFIGURE 3 in conjunction with a plug.

FIGURE is a development of the sleeve of FIG- URES 3 and 4.

FIGURE 6 is a side view of .a plug contact used in a socket according to the present invention.

FIGURE 6a is an end view of the plug contact of FIGURE 6.

FIGURE 7 is -a side view showing the plug contact of FIGURES 6 and 6a in conjunction with a sleeve essentially as shown in FIGURES 3 and 4.

FIGURE 7a is an end view of the arrangement shown in FIGURE 7.

FIGURE 8 shows the coaction of a unilaterally slitted sleeve with a plug; this arrangement does not form a part of the present invention.

Referring now to the drawings and to FIGURE 1 thereof in particular, the same shows the male component, or plug, having a steel casing 1, into one end of which leads a cable 2 passing through a clamping cone 3 so as to provide a Water-tight seal between the plug and cable. The contact elements proper are shown at 4a, 4b, 4c, and the same =are hollow or annular so that the cable conductors can pass therethrough.' The contact elements can be soldered or cinched to the cables so as to effect a good electrical connection. The coaxially arranged, stepped contact 4a, 4b, 4c, are mounted on 4an elastic plug rod made of plastic material and are spaced from the end into which the cable 2 leads. In practice, it is expedient to increase the rmness of the connection and the seating -of the contacts on the plastic rod by suitably profiling the same,l such as by the provision of abutments or interior riing. According to the present invention, the layer 6 of the plastic plug rod consists of an epoxy resin which can be worked Icold under normal pressure; the filler layer 5 is similarly constituted by an epoxy resin. However, by admixing the proper amounts of poly-mer, the Shore hardness of the layer 5, located in the region where the ca'ble leads into the plug, is brought t-o a value of approximately 100, while the layer 6, located in the region of the contact elements proper, is admixed with polymer in such a ratio that the Shore hardness of the layer 6 is substantially lower, namely, approximately 35.` The plug further includes a clip 13 for pretensioning the cable prior to the casting.

The female component, or socket, shown in FIGURE 2, comprises a steel casing 7. A cable 9 is introduced into the casing 7 and is sealed in by means of a sealing tand tensioning cone 8. As in the case of the plug, the In the region where the cable is introduced into the casing 7, the cast mass 10 has a Shore hardness of about 100, while in the region of the concentric and stepped contact elements 12a, 12b, 12C, arranged to make contact with the contact elements 4a, 4b, 4c, respectively, of the plug and also soldered, cinched, or otherwise securely fastened to the inner wall of the mass 11, this mass has a Shore hardness of about 65.

The constituents which make up the sealing material are initially in liquid state, are hardened or set, in conventional manner, 'by adding a hardener.

It is best to make the transition from the region of one 'hardness to the region of the other hardness gradual The plug of FIGURE 1 and the socket of' FIGURE 2 'can be coupled together so that the contact elements 4a,

4b, 4c engage the contact elements 12a, 12b, 12C, re-

spectively, of the socket. The exposed portions 14 and 1S of the steel casings 1 and 7, in the region of theseal, are lined with hard chrome to prevent corrosion. An outer seal is formed by means of gaskets 16 made of rubber or plastic and having an oval cross section, while the main seal is constituted by the conically shaped fitted seats 17 (FIGURE 1) 'and 18 (FIGURE 2) which, when the plug,r is forced into the socket, will be wedged together. Y

FIGURE 3 shows a sleeve 21 made of conductive material; such a sleeve may be used for the Contact elements 12a, 12b, 12C, of the socket of FIGURE 2. The sleeve is provided with longitudinally extending slits 22 alternate ones of which start at opposite ends of the sleeve and extend past the middle of the sleeve so as to overlap, `as shown. Each end of the sleeve is provided with a collar or flange 23.

FIGURE 4 shows the sleeve of FIGURE 3 in conjunction with an annular or tubular metallic contact element 24 of the plug which has been inserted into the sleeve.

FIGURE 5 shows the sleeve 21 of FIGURE 3 in de velopment. 1

FIGURES 6 and 6a show a modification of the metallic contact elements -of the plug. The same is not strictly cylindrical but has two flanges 26, as does the sleeve of FIGURES 3 -to 5. Thus, there is formed a section 27 which has a reduced diameter. It is particularly advantageous to make the flanges 26 of laminated raised strips 28 which lie at an angle to the axis of the connection. Alternatively, the anges can be formed by a slot-cutting operation. The purpose of the flanges or collars is to produce a self-cleaning action when the plug is inserted into the socket, because foreign bodies will then escape into the interspaces between the strips 28.

FIGURES 7 and 7a show a connection established by g means of a plug according to FIGURES 6 and 6a and a socket 29 which is similar to that of FIGURES 3 and 4. Shown also are the connecting terminals 30 for the cable.

The above-described contact arrangement has the advantage that, instead of there being an undesired circular engagement between the cylindrical plug and sleeve, a lowwear surface contact is obtained. TheI sleeve arrangement of FIGURES 3 and 4 makes it possible for the tongues formed between the Vlongitudinal slitsof the sleeve to change their position twice, once when the plug penetrates the first ilange of the sleeve and again when the plug penetrates the other flange. The rst time each tongue changes its position, it moves from the axially parallel orientation to an inclined orientation, and as soon as the plug engages the flange at the other end of the sleeve, the tongue will be moved back to its axially parallel orientation. This will cause the tongue portions of the sleeve to lie against the plug with increased force and the surfaces of `the flanges will lie at lagainst the plug. Such an arrangement is superior to the prior-art arrangement, lsh-own in FIGURE 8, in which the sleeve is slitted from but one side, because there'the surfaces of the sleeve will not lie flat against the plug. Here it is to be borne in mind that,in drilling operations in particular, no particular attention is paid to establishing the electrical connection since :the persons doing the work will generally take it for granted that electrical contact will be properly established, and they will not wish to concern themselves with attending to this detail. As is well known, the tubular sections are joined by twisting the coupling sleeve, and it is expected that the cable connection, which lies con- Centrically within the tubing, will, as a matter of course, be properly made. It is therefore particularly important that ,the wear between the parts which are so mounted as to be rotatable about the axis of the tubing be asis'mall as possible.

It will be appreciated that a connector arrangement as described above allows all of the necessary assembling to be done at the drill site. The introduction of the sealing material does not require any heat treatment orv other Work f Q b@ done at the time of assembly, furthermore,

everything can be carried out at normal pressure. The seal that is obtained is, nevertheless, absolutely tight. Additionally, the connector arrangement according to the present invention is reliable, is self-cleaning, results in little wear, produces good surface-contact, and oifers a robust mounting in the tubing, all of which is particularly desirable where rough handling is encountered, and where water and dirt must be kept out lof the cable connection, as is the Case in a drilling operation.

The sealing material consists preferably of a bisphenol epoxy resin with an epoxy equivalent of from 200 to 250, thiokol polymer, and aliphatic amine hardener. For the region ofthe lead-in means e.g.

100 parts of bisphenol epoxy resin, 8 parts of aliphatic amine hardener and 5 parts of thiokol polymer are used, for the region of the contact means, however,

100 parts of bisphenol epoxy resin,

8 to l2 parts of aliphatic amine hardener and from 60 to 130 pants of thiokol polymer are used.

Thus after curing at room temperature of the sealing material it will be found that it shows a Shore hardness of approximately 100 for the lirst composition and approximately from 65 Ito 35 for .the `second one.

In a preferred embodiment of the invention,

100 to 150 parts of bisphenol epoxy resin, 8 parts of aliphatic amine hardener and 100 parts of thiokol polymer are used for the region of the contact means, while the composition for 4the lead-in means is the same as described above.

Thus after curing at room temperature of the sealing material it will be found that it shows a Shore hardness of approximately 100 for the iirst composition and approximately 50 for the second one.

In another embodiment of the invention, 80 to 100 parts silica-powder may be added to all the compositions for the region of the lead-in means.

It will be understood that the above description of the present invention is susceptible 4to various modifications, changes and adaptations, and Ithe same are intended to be comprehended within the meaning and range of equivalents of the appended claims.

What is claimed is:

1. A connector arrangement adapted for attachment within drill tubing and comprising a plug component and a socket component each having a casing, lead-in means for a cable at one end of the casing, contact means spaced from said one end of the casing for establishing electrical contact with the contact means of the other component, and a first sealing mass between said casing and said contact means and a second sealing mass between said casing and said cable lead-in means; each sealing mass comprising at least one epoxy resin constituent and at least one polymer constituent and being a mass which can be worked cold at normal pressure, the ratio of the constitu- I ents of said second mass in the region of said lead-in means being such that its Shore hardness is approximately while the ratio of the constituents of said rst mass in the region of said contact means is such that its Shore hardness is in the range of approximately 35 to 65.

2. A connector arrangement as defined in claim 1 wherein the contact means of said socket component comprise a sleeve which is axially slitted by a plurality of slits whose length is less than the :total axial length but more than half the axial length of said sleeve, different i 3. A connector arrangement as dened in claim 2 n wherein said contact means of said socket component are hollow cylindrical.

4. A connector arrangement as dened in claim 2 wherein said contact means of said socket component are provided with two axially spaced-apart contact-making flanges forming between themselves a portion of reduced diameter.

5. A connector arrangement as deined in claim 4 wherein said flanges of said contact means of said plug component are constituted by laminated raised strips which lie at an angle to the axis of the connector arrangement.

6. A connector arrangement as defined in claim 1, wherein the contact means of said plug component each are provided with a sleeve which has axially spaced apart two outwardly extending contact-making ilanges forming between themselves a portion of reduced diameter.

7. A connector arrangement as defined in claim 6, wherein the Contact -means of said plug component respective anges are constituted by laminated raised strips which lie at an angle to the axis of the connector arrangement.

References Cited by the Examiner UNITED STATES PATENTS 1,123,060 12/1914 Abbott 339-251 X 1,901,894 3/1933 Burke 200-127 2,225,728 12/ 1940 Weidenman 339-60 2,409,004 10/ 1946 Wall 339-60 2,881,406 4/1959 Arson 339-59 2,930,773 3/ 1960 Renfrew 260-47 X 2,970,971 2/1961 Katz 260-47 X 3,060,417 10/1962 Blake 340-227 3,193,636 7/ 1965 Daniels 339-182 X FOREIGN PATENTS 1,017,241 10/ 1957 Germany.

892,801 3/ 1962 Great Britain.

OTHER REFERENCES Hickson, R., Electrical World, April 5, 1954, page 140.

EDWARD C. ALLEN, Primary Examiner.

ALFRED S. T RASK, Examiner. 

1. A CONNECTOR ARRANGEMENT ADAPTED FOR ATTACHMENT WITHIN DRILL TUBING AND COMPRISING A PLUG COMPONENT AND A SOCKET COMPONENT EACH HAVING A CASING, LEAD-IN MEANS FOR A CABLE AT ONE END OF THE CASING, CONTACT MEANS SPACED FROM SAID ONE END OF THE CASING FOR ESTABLISHING ELECTRICAL CONTACT WITH THE CONTACT MEANS OF THE OTHER COMPONENT, AND A FIRST SEALING MASS BETWEEN SAID CASING AND SAID CONTACT MEANS AND A SECOND SEALING MASS BETWEEN SAID CASING AND SAID CABLE LEAD-IN MEANS; EACH SEALING MASS COM- 